Process of coking a mixture of a carbonaceous material and a high boiling bituminous pitch



Patented Oct. 20, 1953 .P-ROCESSTOFCOKING A MIXTURE OF A CAR- BONACEOUS vNIATERIAL AND A 'HIGH BOILING BITUMINOUS PITCH "Walter TJBrown, Pittsburgh,.1a.

NoDrawing. Application February 5,1951,

'S eria'lNo. 209,519

7 .181Claims. (Cl. 202-33) Thepresent invention relatesto a cokingprocess and, more particularly, to a process 'for'producing high quality coke, such as --meta1lurgical coke, from coke lines and polymerized bitumen in a bottom-heated, horizontal retort or coking chamber, without briquetting.

Broadly stated, the present invention relates to a coking process for-producinga high quality coke from dried coke 'fines-or braize'of less than 4" size GA in) or other non-coking bituminous material which is mixed with a -high softening point coaltarpitch or other" bituminous material :composed principally of unsaturated polynuclear hydrocarbons; which mixture .is heated in'a horizontal retort or coking chamber, the bottom of which "is heated sufii-ciently to cause polymerization of the hydrocarbons and formation of a solid cake of coke. V 'Theicoal tar pitch (or other bituminous material) when heated becomes ,liquid and flows, thereby -thorou hly wetting all the cells and pores of the coke fines and filling the interstices between the cokeparticles. Thenthe :high boiling "cyclic, polynuclear hydrocarbons are polymerized by heat to form longchain polym'ersthat"thoroughly cementjthe coke particles together. vFurther heating inthe' coking retort "depolymerizes the mass, with an evolution of some hydrogen and ammonia, whereby thecoke particles and'thepolymerizedbitumenccoalesce and form'a solid cake of high quality coke=which physical coke tests Shawnee high shatter-and. stability 'properti-es. *This'coke may be crushed to any desiredsize "for use in blast furnaces'or for other purposes. v

The coking process embodying the present' -inventioniis' limited to the useof a fiat, level, horizontal, bottom-heated retort or'coki'ngchamber of :any design. The coking .process scannot be successfully accomplished .in anverticalretort :or

thestandard, vertical, slot-type; byproduct coke oven (such as 'Koppers, Wilputte, ;-.Semet-Solvay,'

' Otto and others) because the --coa1;ta,r;-pitch (or or glue, whereby the coke particles, coal fines, anthracite culm, etc are cementedtogether by.

pressure in a briquetting pressvof any suitabledesign. The present coking process involves a' high softening point coal tar pitch or similar bitumen composed chiefly-of polynuclear hydrocarbons, which can be polymerized. "Thiszbit u minous material would .be unsuitable for use as a binder or gluein a briquetting process, because it is brittle and has .little cementing properties.

Also,the coking processembodying the present invention should not be confused with processes for producing petroleum cokeor pitchlcoke, which hot, residualoilor pitch '-is sprayed into a retort or cokingchamber, whereintdestructive distillation depolymerizes the iresidual .=oil or pitch, leaving ca carbon residue, known :as "petroleum coke or pitch.-coke, which is usediinsthe manufacture of carbon ,1 electrodes. V

Coke fines Coke .flnes, also called coke braize or coke breeze, .is produced in the-manufacture, crushing, handling andouenchin of, by-zp oduct or beehive cokezfrom bituminous coals. In cokeplants producing blastgfurnacecoke, the WI ,X0 or 5%", 13x0 size is screened out ,as vcoke braize or coke .afines. There is a considerable qu n ty cok fines produced, which-,isoflittle or no value. H

@At .some-cokeplants, the ry x size screened out of the coke braize or finesland-sold or used ,in gas producers or. for other purposes. Alsq some coke plants burn thecoke braizeunder steam boilers but the 8'. ex 0 size coke fines are generally not burned and blow out the stacksor, settle in the waste gas ,fiues, thereby constitute a waste by product. A

In chemical plantszmanufacturing; calcium car.- bide, in electric furnaces, the by-product or. beehive I coke .is crushed to 1" ,x 0 [size and the Q19 mesh x 0 very finesize coke ,is screened out. There .-is approximately ten ((10%) percent of the 10:mesh x ,0 size'coke fines which is awaste material. Many attempts have ,beenflmade at coke andchemical plants to utilize the fl -oi-o size,coke;finesby briguettingvand other methods, but these have notbeen very successful. I r

Cokehasa .cellularsandporou -structure com taming manycells orrmacro andmicropor esor capillaries. fIhe (coke lines ,used ;in the present invention are /4 ,x' -fimsize-andzareiof thersame porous istructur abut 1containamoresmacroiand micropores-ztherefore should beithoroughly-dried to remove any moisture from: these. capillaries .or micro poressoithegcokeicaniber-thoroughly wetted by the coal tar pitch or other bitumen. Coal tar pitch when heated to 400 F. or higher has a low surface tension. Materials having a low surface tension are better wetting agents. The coal tar pitch or bitumen used in the present invention thoroughly wets and penetrates all the macro and micro pores of the dried coke fines before being polymerized.

Coal tar pitch or bitumen The present coking process is limited to the use of coal tar pitch or other bitumen composed principally of unsaturated polynuclear hydrocarbons of various high softening points. Coal tar pitch is a pyrogenous bitumen, because it is produced from bituminous coals by heat or fire and is composed principally of unsaturated hydrocarbons.

Other pyrogenous bitumen, such as pitches produced from oil-gas tar, water-gas tar, wood or pine tar, lignite tar, shale tar, bone tar, rosin pitch and fatty-acid pitches, are not suitable for use in the present coking process, because none of these pitches contains the high-boiling, cyclic hydrocarbons, which will polymerize and thoroughly cement the coke particles in the coking process.

Coal tar and coal tar pitch Coal tar is produced in by-product coke ovens or retorts of various designs by the carbonization of bituminous coals. The quantity and quality of the coal tar produced depends upon the coals or coal mixture used, design of the coke oven or retort, coking time and carbonization temperature.

Coal tar is a carbon-olesol, that is, a colloidal solution of micro and ultramicro size carbon particles in an oily solution. These carbon particles, when, observed under the cardioid ultramicroscope, *have a rapid Brownian movement. The finely divided carbon particles are called micelles (micelles are the organic molecular aggregates occurring in colloidal solutions) and are the lyophobic portion of the colloid solution. The protective bodies are known as the lyophilic portion of the system and are composed of heavy hydrocarbon oils, such as anthracene, phenanthrene, pyrene, chrysene and other polynuclear, cyclic hydrocarbons. The light oils, carbolic oils and creosote oils have no value as protective bodies for the micelles and are easily removed by distillation. The micron size is 0.000020 c. m. and the ultramicron size is 0.000001 Cardioid ultrarnicroscope studies of coal tar show that the carbon particles or micelles measure 0.0000148 o. m., which is between the micron and ultramicron sizes. These studies also show that one gram of coal tar contains 513 billion carbon particles or micelles.

Coal tar is commercially distilled in various designs of batch and continuous tar stills and tar heaters in order to recover the light oils, carbolic oils and creosote oils which are the most valuable constituents of coal tar and have a ready market. The residue is coal tar pitch which may be produced to have any desired softening point, depending on the amount of oils distilled off, such as road tars, roofing pitch, briquette pitch, fuel pitch, etc.

When the distillation of coal tar is carried to high-melting point pitches to obtain heavy oils for creosoting or other purposes, a less valuable pitch is obtained, called hard pitch or fuel pitch,

which is best suited for use in the present coking process.

The largest recovery of distillate oils is obtained when coal tar is distilled in a continuous fractionating still under vacuum. When coal tar is distilled in a simple batch still or tar heater, the yield of distillate oils is lower and there is cracking or depolyermization of the residual pitch. The cracking ruptures the protective bodies (heavy hydrocarbon oils), causing the carbon particles to be released and are shown as clusters without Brownian movement in the cardioid ultra-microscope, and laboratory tests shown an increase in free carbon.

The coal tar pitch used in the coking process embodying the present invention is composed of carbon particles in a medium of high-boiling (above 300 C.) cyclic, polynuclear hydrocarbons.

The cyclic hydrocarbons comprise phenanthrene, anthracene, naphthacene, tetramethylanthracene, pyrene, chrysene, picene, etc.

The cyclic hydrocarbons, particularly the tri, tetra and penta cyclic or polynuclear hydrocarbons, are readily polymerized by heat to form giant polymers of high molecular weight. Polymerization is a chemical reaction involving a successive addition of a large number of relatively small molecules (monomers) to form a final compound or polymer.

Steps in the coking process 1. In carrying out the present invention, the x 0 coke fines (or other non-coking bituminous material) are thoroughly dried by means of a flash dryer, multi-louvre dryer, roto-louvre dryer or" other means, to remove the moisture from the cells, or macro and micro pores of the coke fines. This will prevent foaming of the coal tar pitch, or other bituminous material composed substantially o unsaturated, polynuclear, high boiling, cyclic hydrocarbon, and permit the bitumen to flow freely and penetrate into the cells, pores and capillaries of the coke fines and to fill the interstices between the coke particles. The waste flue gases from the coking retort may be used for drying the coke fines, or ainy other means of heat or hot gases may be use 2. The coal tar pitch or other bitumen is flaked or crushed to /8" x 0 size and blended with the dried coke fines in the proper proportions to produce the quality coke desired.

Successful coking was accomplished with 75 by weight, of x 0 coke fines and 25%, by weight, of coal tar pitch, to produce a highquality coke with as high as 52 stability factor in the tumbler test.

The coal tar pitch or bitumen may be heated until it is a liquid and sprayed on the hot, dried coke fines, or mixed with the dried coke fines by any desired means. The coating of the coke fines with coal tar pitch will prevent any reabsorption of moisture and produce a mixture of non-coking, bituminous fines and bitumen of the proper proportions for charging into a coking retort. A high-quality coke has been successfully produced by this method.

3. The mixture of dried coke fines and coal tar pitch or other bitumen is charged into a flat, level, horizontal, bottom-heated coking retort or ove n chamber of any design, which is heated by gas, oil, tar, pitch or electricity or any other means of heating. Such retorts and ovens, per se, form no'part of the invention, being well azeeegsoe" 5, known? im the: art and describedi 1m United: states patenrsi such as: the tolloiwingt Hi'i'ghes, 225923801, October" 141, 1941;

Hughes; 232343173; March r13, 1941;;

Knowles etatfi, 11 885,920; November 1;, 1932:; Curran}. 2126?,44'71, necemb'erzs, 1941 The temperature of; the; bottom: of the; coking: retort should; not: exceed; 18.00? F. and b.est"re- Higher? temperatures; distilli om the: heavy hydro? carbom oils; from. the pitch:- before-they have; ai chance; to: polymerize;

Thefcoking; retortvmustbeiflatg,level; and hornzontah.- andi heated: from: the bottom only; and: may be constructed of metal;silicaabriclhsilicon oarbidei (-Earboframi or any; other suitable heat resisting: material; The endszofi themokingi l etort; should: have closures or: doors; which: Willi hermetically sealythe; coking: retort. ga's offs takes should; be; provided at or 'near the top; oftthe; retort to removesanyj gassevolyeda- 'I hegases can be; vented: to: the atmosphere: or; collected: in the: conventional by-product recovery: apparatus:-

4-,. Theeh'eat inthe bottom of thecoking-i retort; causes; the: coal, tar pitch: to; melt and: flow: into all the cells, pores and capillaries of the coke; fines; and fill in? all: the interstices between the coke particles More specifically the'heat from: the-bottom ofithe cokingretort' lowers the surface: tension' ofthe;coalitaz'vpitchzso that. it-thoroug-hly wetsv and penetrates; ailtthe: cells; pores; andcapil laries; Off. the dried: coke; fines;

'Iihe; heat from the bottom of the coking retort.- thcn; causes; the? high-boiling" cyclic po1y-nuc1ear= hydrocarbons t'of polymerize" within; and. around. the cokerparticles thereby producing; giant polymers. On furthen-heating 'the coke finesrandthez polymerized! bitumen coalesce forming a, solid cake; of high-quality coke. The: unpolymerize'd or'partially polymerized hydrocarbons etc are; depoly-merized with the: evolution, of: hydrogen andrammoniaa 5. The coke: produced is discharged froma-thes coking retort-or chamber by any suitable means The. depth of the mixture of coke,- fines ands coabtar pitch, or otherbitumen in thfiflalk. hori zontal, bottom-heated coking-i retort is; limitedi by the coking temperature. and-the amount ofc'oali tar pitch: used, but-should not exceed, 12 inches imdepth. However, it is possible that further development of the present coking, process: mayprove that} a greater depth of. mixture: of coke finesand coaltar pitch may be carbonized satis I factorily. Best-results have-been obtained-with depths of' ito 8 inches.

The coking rate, of the presentcok-ing, process will depend on the cokingt'emperatureand depth of. charge in the coking retort. High. quality coke has been produced. by the present coking process at the rate of 1 inch to' 115 inches per hour. The present invention, however; is notlimited to any specified cokingrate.

Other applications of the present coking; process The coking process" embodying the" present in,- vention" is not limited to'the production ofmetal lurgi'cal coke: from coke fines and coal" tar pitch or other-bitumen, because high quality coke" may" be produced from mixtures of high medium or low volatile bituminous coking: coals; cokefines; coal; ta-r pitch; ort'other bitumen;

Alsmthe present 'CDRiIlg! processim'ay be utilizedi ilorr coking a: mixture of: non-coking or; poorly coking coals or chars (suoh as high 1 VO1a17i1EE'-C,'"

6 subs-bituminous,.sennwnthracite:.authraciteilcotili chars or lignite chars) with coal tar pitclii out othersuitableibitumenfl High quality make has been? producedl by the present coking process? from the: followingi'miir ture'si (by-weight) oi bituminous-coals, cokefines and 002311 tar pitch 1'. High volatile coal 25%;; coke fines 50%;. coal tarpitch 25%. 1 2: Medium volatile coal 25%;- coke fines 5.63%:

coal" tarfpit'chi 25%.

31 Low volatile coal 25%.; colic. fines" 507%;

tar pitch 25%. 4 4:. Medium volatile co'al 55%;. coke? fines 30%;; coal'tar pitch 15%.,

5'. Mediiim volatile" coal 66%3, cfok'e. fiiies 36%;:

coalitar'pitch 111%..

The above compositions are recited merely by 21F way ofilliistratiom and are i not" to" be considered as limitin the scope oitheinventiom inasmuch as variations may be made in the per-centage's enumerated with satisfactory results;

The present coking processmay be" utilized in are'as a-way from the-bituminous; coking coai' pro ducing districts for the production of metallhfi gical, foundry or domestic cokes front p'oo'rlivcoking or non-coking co'a'l's; or coal fines,- orchar, which at the-present time cannot be utilizedfb'rf the manufacture of coke The use" of oorly-coking or non-coking crisis;- or coal fines, or char for the prodiict-ionofmetal lurgical or domestic cokes by the present processwould conserve the reserves-=of-' highqua'lit'y; cok 1 ingcoals and aid in-the e'conomyof the 'count ry:

It is de'sirable to-u'se' a'mixture-oi 55% medium volatile, bituminous coking coal, 30% cokefi'hes' and 15% coal tar pitchor other suitablebitumen in the present coking process; imorderto' suppl'y" sufficient coke oven gas for'heatihg the coking? retort, to reduce;- the amount" of coal tar pitch (or other bitumen) required and to supply sufli cient'coaltar for distillation to a; high-softening point, coaltar pitch; in this way the colfiiig 4? process is: sel-f -sustaining and it isnot necessary toisupply or'purchase-gas or other fuels for h'eat in'g theicoking retort or coal. tar pitch necessary fo'r'the prhc'es'si 1 However, other: mixtures than those specificallkz 5m recited above maybe -us'e'd in therange ofll% to 60%,bituminous coking coals,- 10 to75-%- wee fines, and 10%- to 25% coal tar pitch (or equiv alent), by weight.

High-volatile, bituminous, coking coals have-a very fluid plastic zoneywhenbeing converted from coal to coke; which is readily 'volatili'zed during carbonization, leaving a poorly consolidated cokei Low-volatile; bituminous; coking'coalshave a very" viscousplastic zone when being converted from ooal to -coke during: carldenization, but thisf plastic zone is-very-thin and'-onlya small quantity of gas and coal tar is produced during carboni zation which would: not be-sumcientto make the coking process self sustainingl Medium volatile, bituminous, col-ingcoals'havei: a: thick, viscous plastic zone-whe'n being coirverted from coal to coke during carboni'zatibn;- The use of suflicient medium-volatile bit'uminous, coking coals' ih the present coking prodesswithcoke fi'nesand'coal tar pitch wilFsupply sufli'cient gas for heating the coking retort, re duce the quantityof coal tarpitoh required; and furnish su'fiici'ent coal tar: for distillation" i70 Coal! tar pitch: tc make? the" coking:- p'rocessr selresussx taming-3 and supply; light; carbolicr and creosote oils for sale, thereby reducing the operating costs of the coking process.

It should be noted that in the present specification wherever coal tar pitch is specified, other equivalent bitumens, namely, those composed essentially of unsaturated, polynuclear, cyclic hydrocarbons, can be used instead, preferably those having a softening point in excess of 250 F., A. S. T. M. ring and ball (or a melting point of greater than 300 F.) cube in air method. Also, where coke fines are mentioned, other non-coking, bituminous materials may be substituted therefor.

Thus it will be seen that in accordance with the present invention, there is provided a highly efiicient, economical process for making use of coke fines, normally a waste product, which are agglommerated with bituminous material to form a cake of high quality coke, such as metallurgical coke.

While I have illustrated and described several specific embodiments of my invention, it will be understood that these are by way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim:

1. A process for producing coke, which comprises mixing dry, non-coking, carbonaceous material with bituminous material composed essentially of unsaturated, polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a horizontal, bottom-heated retort to a temperature to cause polymerization of the hydrocarbons and formation of giant polymers having substantial bonding characteristics.

2. A process for producing coke, which comprises mixing dry coke fines of less than particle size with bituminous material composed essentially of unsaturated, polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a horizontal, bottom-heated closed chamber to a temperature below 1800 F. but sufiiciently high to cause melting, flow and polymerization of the hydrocarbons.

3. A process for producing coke, which comprises mixing 25% to 75%, by weight, of coke fines of less than 4" particle size with 75% to 25%, by weight, respectively, of bituminous material composed essentially of unsaturated, polynuclear, cyclic hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal coke oven at a floor temperature below 1800 F. but sumciently high to cause polymerization of the hydrocarbons.

4. A process for producing coke, which comprises mixing of the order of 75%, by weight, of coke fines of less than particle size with 25 by weight, of bituminous material composed essentially of unsaturated, polynuclear, cyclic hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottomheated, horizontal retort at a. fioor temperature below 1800 F., but sufiiciently high to cause polymerization of the hydrocarbons.

. 5. A process for producing coke, which comprises mixing dry coke fines of less than 4" particle size with coal tar pitch having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal retort at a floor temperature of the order of 1600 F. to cause polymerization and bonding by the hydrocarbons.

6. The method recited in claim 5 wherein the 8 coke fines comprise about 75% and the coal tar pitch, about 25%, by weight, of the mixture, and wherein the coal tar pitch is composed essentially of unsaturated, polynuclear, cyclic hydrocarbons.

7. A coking process for producing coke, which comprises mixing thoroughly dried coke fines of less than A size with ground bituminous material composed essentially of coal tar pitch having a boiling point above 300 C., said coal tar pitch substantially comprising unsaturated, polynuclear, cyclic hydrocarbons, and heating the mixture in a bottom-heated, horizontal retort or coking chamber at a fioor temperature of between about 1400 F. and 1800 F. so as to cause polymerization of the hydrocarbons and formation of a solid cake of coke.

8. A process for producing coke, which comprises mixing substantial quantities of bituminous coking coal, coke fines of less than about inch particle size and bituminous material composed essentially of unsaturated polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom heated horizontal coke oven to a fioor temperature of the order of 1600 F. to cause polymerization of the hydrocarbons and formation of a solid cake of coke.

9. A process for producing coke, which comprises mixing 10% to 60%, by weight, of bituminous coking coals, 10% to 75%, by weight, of coke fines, and 10% to 25%, by weight, of bituminous material composed essentially of unsaturated polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal coking chamber to a temperature below 1800 F. but sufficiently high to cause melting, flow and polymerization of the hydrocarbons.

10. A process for producing metallurgical coke which comprises mixing of the order of 25%, by weight, of bituminous coking coal; 50%, by weight, of coke fines and 25%, by Weight, of coal tar pitch comprised essentially of unsaturated polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal coking retort at a floor temperature below 1800 F. but sufiiciently high to cause polymerization of the hydrocarbons and formation of a cake of coke.

11. A process for producing high quality coke, which comprises mixing about 55%, by Weight, of medium-volatile, bituminous coking coal particles, 30%, by weight, of dry coke fines smaller than size and 15%, by Weight, of particles of coal tar pitch comprised essentially of unsaturated polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal coke oven at a fioor temperature of between 1400 F. and 1800 F. to cause polymerization of the hydrocarbons and formation of giant polymers having substantial bonding characteristics.

12. A process for producing high quality coke, which comprises mixing about 60%, by weight, of medium-volatile, bituminous coking coal particles; 30%, by weight, of coke fines of less than 4" size, and 10%, by weight, of coal tar pitch comprised essentially of unsaturated, polynuclear hydrocarbons having a boiling point in excess of 300 C., and heatin the mixture in a bottomheated, horizontal retort at a floor temperature of between 1400 F. and 1800 F. to cause polymerization of the hydrocarbons and formation of a solid cake of coke.

13. A process for producing coke, which comprises mixing coke fines, bituminous coal and coal tar pitch comprised essentially of unsaturated polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal retort sufficiently to melt, flow, Wet and penetrate the cells, pores and capillaries of the coke fines and polymerize the unsaturated cyclic polynuclear hydrocarbons of the coal tar pitch and thereby thoroughly cement the coke particles together.

14. A process for producing coke, which comprises mixing 25% to 75%, by weight, of noncoking, bituminous material of less than 4" particle size with 75% to 25%, by weight, respectively, of bituminous material composed essentially of unsaturated, polynuclear, cyclic hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a bottom-heated, horizontal coke oven at a floor temperature below 1800 F. but sufficiently high to cause polymerization of the hydrocarbons.

15. A process for producing coke, which comprises spraying hot, melted bituminous material composed essentially of unsaturated, polynuclear, hydrocarbons having a boiling point in excess of 300 C., upon hot, dried, non-coking bituminous material prior to charging into a horizontal retort, and heating the mixture in a horizontal retort to a temperature to cause polymerization of the hydrocarbons and formation of giant polymers having substantial bonding characteristics.

16. A process for producing coke, which comprises spraying hot, melted coal tar pitch composed essentially of unsaturated, polynuclear, hydrocarbons having a boiling point in excess of 300 C., upon hot, dried, coke fines prior to charging into a horizontal retort, and heating the mixture in a horizontal retort to a temperature to cause polymerization of the hydrocarbons and 10 formation of giant polymers having .substantial bonding characteristics.

17. A process for producing cake, which comprises spraying hot, melted coal tar pitch composed essentially of unsaturated, polynuclear,

hydrocarbons having a boiling point in excess of 300 C., upon hot, dried, coke fines prior to charging into a horizontal retort, and heating the mixture in a bottom-heated, horizontal retort or coking chamber at a floor temperature of between 1400 F. and 1800 F. so as to cause polymeriza- .tion of the hydrocarbons and formation of a solid cake of coke.

18. A process for producing coke, which comprises mixing dry, non-coking, carbonaceous material, and of less than 4" particle size, with bituminous material composed essentially of unsaturated, polynuclear hydrocarbons having a boiling point in excess of 300 C., and heating the mixture in a horizontal, bottom-heated, closed chamber to a temperature in the range of about 1400 F. to 1800 F. to cause melting, flow and polymerization of the hydrocarbons.

WALTER T. BROWN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 21,651 Rice Dec. 3, 1940 1,308,754 Graul July 8, 1919 1,717,884 Knowles June 18, 1929 1,884,339 Steere Oct. 25, 1932 FOREIGN PATENTS Number Country Date 259,427 Great Britain Oct. 14, 1926 393,297 Great Britain May 30, 1933 384,956 France Aug. 13, 1942 563,366 Great Britain Aug. 10, 1944' 

1. A PROCESS FOR PRODUCING COKE, WHICH COMPRISES MIXING DRY, NON-COKING, CARBONACEOUS MATERIAL WITH BITUMINOUS MATERIAL COMPOSED ESSENTIALLY OF UNSATURATED, POLYNUCLEAR HYDROCARBONS HAVING A BOILING POINT IN EXCESS OF 300* C., AND HEATING THE MIXTURE IN A HORIZONTAL, BOTTOM-HEATED RETORT TO A TEMPERATURE TO CAUSES POLYMERIZATION OF THE HYDROCARBONS AND FORMATION OF GIANT POLYMERS HAVING SUBSTANTIAL BONDING CHARACTERISTICS. 